swilli89

Update 1: so the amp appears to be fully functioning. I spliced into the front right door speaker at the amp output, pulled the speaker, connected it in the trunk and it sounded great. Pictures below.



Hello all. I need some help in diagnosing and fixing what is going on with my car's audio system.

• ALL 4 door speakers not working
• Front tweeters work, back sub work fine

Everything electrical is fine in the car that I know of, all fuses have been checked and are not blown. The car has a brand new battery and the alternator is fine, as well as I have full function of my radio head unit (factory ML non-nav unit).

The amp seems to be functioning somewhat because I get good clear volume from both tweeters and sub. I checked with a multimeter and I get zero current or signal to any of the door speakers from the amp, but I have not yet checked at the amp because I haven't found the wiring diagram that the broken link in the ML thread points to.

Here is where it gets sort of interesting... (note sorry pictures are so bad, spent half an hour out of my only day to work on the car to try and figure out a way to downsize them.. nothing seems to work).



Picked up a 2002 LS430 205k miles last week




Factory Non Nav ML Headunit




Hmm well this is interesting




Hmm a high freq/loq freq breakout box.. shouldn't really be affecting anything, right?




These little door dome tweeters were installed at some point in the car's life. They are simply from the breakout box above.

I actually never looked close enough, I figured the M standed for Mark Levinson




Memphis Audio 6.75" in front.




ML amp still wired in.. Is this the culprit?

So at some point the previous owner upgraded the door speakers and spliced in tweeters, but everything else indicates that the system should be stock. I have a multimeter handy, and the wires going into the door speakers are dead. I even double checked by attaching a small boom box speaker to the speaker wires and still nothing with the stereo playing.

Unlikely scenario would be all four wires individually shorted out. More likely to me..Either than amp has all 4 dead channels or something is wrong with the head unit?

Can anyone help me out with which pins to check on the amp? Any other suggestions?

2KHarrier

No help on the pins, but I would find the CORRECT ML speakers and replace the Memphis (probably wrong OHM rating) speakers, and more than likely you'll need a new amp. Best guess is the amp over heated and shorted out due to incorrect speakers

swilli89

Should I leave the power and head unit connectors on and touch each bare pin on the amp itself with my multi meter?

Aron9000

I'm betting the previous owner had those door speakers wired up with an aftermarket amp and had subwoofers in the trunk as well. When he traded the car in, he just threw the factory amp back in and took all his aftermarket amps(one for door speakers, one for aftermarket subwoofer in trunk) and stuff with him. He might have also had an aftermarket touch screen head unit in there as well, just threw all the factory crap back in at trade in time.

swilli89

Yeah I thought of that too myself. But it also kind of seems like he just upgraded the door speakers and added tweeters that were just wired directly off the door speakers. From what I've seen it would be pretty tricky to wire in a different amp without breaking a lot of things.

I've been doing troubleshooting and trying to narrow down what might be going on today. So I know that:

• The head unit is sending valid L+ L- and R+ and R-. Evidenced by the fact that both the sub and the tweeters are working.
• All of the none working speakers are coming out of the C connector, which is the connector on the ML amp the farthest to the top when its mounted in the car. However the subwoofer does run off this connector.

Interestingly enough, pins 12 and 13, the black and white wires going into the C connector, are what appear to be the main GRD, they lead to a "J30 junction box".. i'd sure love to locate and make sure its grounded properly...

The only other wires besides ground and the sub/door speakers on the amp's Connector C is B+ and B- which I assume is the battery in? Amp seems to be getting power as I can turn volume to the max on the tweeters and sub and its works fine...

rkw77080

These troubleshooting steps can be useful...

cerushio31

I agree with Aaron9000. It's very likely those were ran by an aftermarket amp that was taken out. I would try to find where the speaker wire ends are and get an aftermarket amp to power them up. It would probably save you a huge headache. Is there any evidence of an aftermarket power wire running from your battery to the trunk?

rkw77080

Factory wires for the front RH speaker are light green and light blue. In your current installation, you have an additional cross-over box to split the signal into HF (high frequency) to the new tweeter, and a LF (low frequency) to the 6.5" speaker. You mentioned that you have sound coming out of the tweeter (I assume you mean the new one on the door, and NOT the factory one on the dash board). This indicates that the factory wires (light green and light blue) are good. If so, one of two things down-stream of the signal wires is bad: the cross-over box or the speaker. I would disconnect the cross-over and twist the factory wires (light green and light blue) directly to the 6.5" speaker wires (red and red/black) and see if the speaker makes sound. Since we don't know the impedance of this after-market speaker, please do not crank up the audio volume for an extended period to avoid possibly overheating your amplifier.

rkw77080

Here's the pin-out information for the 4 door speakers...

swilli89

Awesome thank you! I plan on splicing out the light green and light blue FR connection directly from the amp's connector and trying a speaker right next to it. I got a slight voltage reading from that pair in my multimeter; however I'm not 100% I'm even using the multimeter right. I think I was using AC Voltage.

Great tip and no, I did not notice any amp wiring from the battery. The more and more I look at this, its just the stock system with replaced door speakers with tweeters added via breakout box.

ALSO: pulled a door speaker, connected it to home theater system, the speaker worked great!. So the speakers work fine. Its either the amp or the wiring..

No I do not have sound coming from the added door tweeters. I only get sound from the very front dashboard tweeters and the rear subwoofer.

I also made a little chart pinout table based on the electrical diagram RKW77080 sent. According to the C connector it contains the:

• FR
• FL
• RL
• RR
• SubR
• SubL
• GRD
• GRD
• B+ (not sure what this is, battery I am assuming)
• B2+ (not sure what this is, battery I am assuming)

What is confusing is that I thought I maybe had a problem with the C connector (the top most connector when the amp is mounted sideways). However, the amp is obviously getting power and the sub works fine...

Another note of interest, the Memphis Audio speakers are only 4 ohms while the ML amp likes to send 8 ohm signal. BUT, the way the car is wired with door speakers in parallel with tweeters, does this possibly raise the impedance to closer to 8ohm?

rkw77080

Wiring speakers in "parallel" will actually decrease impedance. However, in your current installation, you have a crossover device which is not a simple parallel circuitry. One way to find out the actual resistance is to leave both tweeter and woofer connected to the crossover unit, then remove the audio signal wires from the "IN +" and "IN -" terminals. Use your multimeter to measure resistance across these 2 terminals.

swilli89

Nice! I will do that!

So I am going to splice out the light green and light blue pins 1 and 8 out of the C connector, and test it with a few speakers I have laying around. If it works then I somehow have faults going to all four doors. If it doesn't then I should probably just stop wasting time and send this amp in for repair, no?

I can't think of anything else SIGNAL wise to check besides maybe the ground. The fact that the sub and dashboard tweeters work means the A connector is receiving inputs from the radio just fine on both channels right?

swilli89

Spliced directly after the connector. So the connector/amp is good.



It worked perfectly directly out of the amp, I retested with the door ends of the light green and light blue, and nothing!

So either its somehow ALL 4 door speakers wires are shorted or damaged, or there was some tom foolery behind the head unit..

Edit: No upon thinking about it, there's no way it could be the head unit/cd player. The fact that the amp is giving a good signal directly into the speaker line should rule that out. So I'm beginning to have the dreadful feeling that I have a short somewhere deep in the car.. I can't really think of anything else to try.

swilli89

What is [IJ1]? Maybe it is what is stopping the signal to the doors. All 4 speakers go through some kind of box like this.

rkw77080

The rectangular boxes identify inter-connections...